Merge pull request #33 from gregory/find_roles_from_mask

ability to retrieve the roles associated to a bitmask

VERSION

@@ -1 +1 @@
-0.8.1
+0.8.2

lib/role_model/class_methods.rb

@@ -23,7 +23,11 @@ module RoleModel
 
       (valid_roles & sanitized_roles).inject(0) { |sum, role| sum + 2**valid_roles.index(role) }
     end
-    
+
+    def roles_from_mask(mask)
+      valid_roles.reject { |role| (mask.to_i & 2**valid_roles.index(role)).zero? }
+    end
+
     protected
 
     # :call-seq:

spec/role_model_spec.rb

@@ -51,6 +51,31 @@ describe RoleModel do
     end
   end
 
+  describe '.roles_from_mask(mask)' do
+    subject { model_class.roles_from_mask(mask) }
+
+    before do
+      model_class.instance_eval do
+        include RoleModel
+        roles :foo, :bar, :third
+      end
+    end
+
+    context 'when roles_mask is 0' do
+      let(:mask) { 0 }
+      it 'returns empty set' do
+        subject.should eq  []
+      end
+    end
+
+    context 'when valid roles_mask' do
+      let(:mask) { 3 }
+      it 'returns the list of roles associated with a roles_mask' do
+        subject.should eq  [:foo, :bar]
+      end
+    end
+  end
+
   [:roles, :role_symbols].each do |role_query_method|
     describe "##{role_query_method}" do
       let(:model) { model_class.new }